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On-board Battery Charger

(On-board battery charger --Battery charger permanently mounted on frame of mobile equipment. This specification does not apply to batteries less than 40 volts nominal used for control circuits only.)

  1. Tram circuit is automatically disabled when battery charger AC input cable is energized.
  2. The AC input cable shall be hardwired into the battery charger. Provisions to protect the cable while stored on the mobile equipment shall be provided.
  3. A maintained contact, push-to-operate, emergency-stop switch shall be placed in a conspicuous place on the vehicle. If the input cable is protected by a ground-wire monitor, the enclosure shall include a ground-monitor test switch. One switch may satisfy both requirements.
  4. A power transformer shall isolate the battery being charged from the incoming power source. Power transformers with concentrically wound primary and secondary windings shall include a Faraday shield.
  5. The transformer primary circuit shall be protected against overload and short circuits.
  6. The secondary circuit shall include short-circuit and overload protection.
  7. The power transformer secondary shall be electrically isolated from the frame ground of the battery charger.
  8. If the battery charger output is connected to the batteries through couplers, an interlock circuit shall be provided to prevent uncoupling under load. The interlock circuit shall remove power from the charger output using either a contactor or a circuit breaker with contacts opening all ungrounded conductors in either the primary or the secondary circuit. The interlock circuit will have a manual reset feature.
  9. A meter or other device that indicates the battery state-of-charge shall be part of each battery-charging circuit.
  10. The battery charger shall include an end-of-charge circuit. The circuit shall either stop the charging circuit or reduce it to a level that can be continued without causing excessive gassing or temperature. This level is normally 3 to 6 amperes per 100 ampere-hours of the battery's six-hour rating. A timer is an acceptable means of providing this protection.
  11. Battery covers shall have vents that direct gases away from the battery charger.